Street-paving roller



H. W. LASTER May 25, 1926. 1,586,157

STREET PAVING ROLLER FiledJune 8 1925 aizjiii/ 67 215411? Patented May25, 1926.

UNITED STATES PATENT OFFICE.

HARRY W. LASTER, 0F OAK PARK, ILLINOIS, ASSIGNOR OF ONE-HALF TO C. H.WHITE, .0]? CHICAGQ COOK COUNTY, ILLINOIS.

STREET-PAVING ROLLER.

Apnlication filed .Tune 8, 1925.

This invention relatesto street paving rollers and its principal objectis to provide a machine for rolling down asphaltic or other hardpavements during the laying thereof, and which will roll down thepavements without leaving any of the usual waves or undulations thatresult when the ordinary street paving roller is used. The invention hasbeen designed particularly for use vin connection with the rolling downof freshly laid asphaltic or like pavements on crowned streets and it isin such places that the tendency for the ordinary street paving rollerto form waves or undulations is particularly noticeable. Vith theordinary street roller having two rollers of the same width, there is atendency for the machine to sway sideways, especially when passing along01' near the crest of the crown of the street, and this swaying motioncauses the outer ends of the rollers to sink into the soft pavementduring the oscillations of the machine, thereby formingthe objectionablewaves or undulations in the surface of the pavement.

I have overcome this defect in street paving rollers byproviding threespaced places of support for they machine, thereby overcoming itstendency to wabble or sway, and I have accomplished this by making oneof the rollers in the form of a double roller or a roller having a.double tread portion, whereby the double roller or double tread portionof one roller may have two spaced places of support and the other rollerfurnishes the third place of support. The, invention, therefore,consists in a street paving roller having a single roller at one end ofthe machine and a double roller, or roller having a double treadportion, with a space therebetween at the other end of the ma- ,chine,the width of the double roller and space therebetween, or the rollerwith the double tread portion and the space between the double treadportions being the same or substantially the same as the width of theother roller and the width of the spacebetween the tread portions beingvrelatively small. The invention further consists in the several novelfeatures of construction and arrangement hereinafter fully set forth andparticularly defined in the claims.

The invention is clearly illustrated in the drawing accompanying thisspecification, in which Fig. 1 is a side elevation of a street pav-Serial No. 35,525.

ing roller (in skeleton form)- and showing a simple embodiment of myinvention applied thereto; Fig. 2 is a plan of the rollers, the frame ofthe machine beingwillustrated in dotted lines; Fig. 3 is an end view ofthe double roller; Fig. 4 is an end view of the single roller and Fig. 5is an end view of a slightly modified form of double roller.

Referring tosaid drawing and first to Figs. 1 to 4, inclusive, thereference character 6 designates the main frame of the ma chine which,as usual, is provided with a steering fork 7 at one end, swiveled in theframe upon a vertical axis and, if desired, said fork may be swiveledalong a horizontal line as shown at 8. As is customary, suitablesteering mechanism 9 is provided for steering the machine. The framesupports a power plant of some form, which may comprise a steam boiler10 and a steam engine 11.

Journaled in the fork 7 is the steering roller 12 of the machine, andjournaled at the other end of the frame 6 is the driving roller 13. Therollers are usually made of large diameter,sometimes measuring from fourto five feet in diameter or more, and the width of rollers issometimesmade as great as four to six feet, although, ofv course, the sizesmentioned are not material to this invention broadly considered. As iswell understood, the machine is a heavy structure intended to roll downrelatively soft or freshly laid, pavements. The driving roller 13 isoperatively connected to the engine 11, by suitable driving gearing, asiswell understood.

One of'the rollers, as, for instance, the driving roller 13, is in thenature of a double roller, the total width between the outer sides ofwhich is the" same or substantially the same as the total width of theother roller 12. The exact construction of the double roller immaterialand in the form shown in Figs. 1 to 3, inclusive, I have illustrated itas comprising a. drum 14 of substantially the same width as the roller12 and having secured thereon by rivets, bolts, or the like, two tiresor bands 15, the outer edges of which coincide withthe outer edges ofthe drum and the inner edges of which are spaced apart to leave a gaptherebetween which is of less than one-half the width than either tireor band 15. The exact thickness of the tire is not material, but I haveshown one that is approximately seveneighths of an inch in thickness.Said tires or hands form two spaced apart tread. portions for the roller13 and to all intents and purposes act as a double roller, the twomembers of which are spaced apart a distance less than one-half thewidth of either tire or band 15, whereby the weight is distributed overpractically all of the total width of the roller.

In the form of the invention illustrated in Fig. 5 the double roller 18comprises two separate rollers 15 spaced apart a distance less than thewidth of either roller 15, the total width, however, of the doubleroller and the space therebetween being the same or substantially thesame as that of the other roller of the machine. In this form of theinvention the two members of the double roller may have a differentialgearing between them, operatively connected to the engine, as is wellunderstood.

In the operation of the machine, it is driven over the relatively softor freshly laid pavement in the usual manner and, because of the doubleroller arrangement, one end of the machine has two places of support, asis seen graphically in Fig. 3. 'Qhis effectively prevents the machinefrom webbling or swaying, especially when traveling along crownedpavings. llhen moving in the direction of the arrow 0, in Fig. 2 thedouble roller leaves a slight ridge in the surface of the pavement, asillustrated in F lg. 3, but when the machin is driven in the directionof the arrow Z), in Fig. 2, the full width roller 12 smooths down theridge left by the double roller, leaving the surface in a smoothcondition. It is understood that the machine is moved back and forthalong the soft or freshly laid pavement a greatmany times during therolling or smootl'iing process, and it is moved along parallel orsubstantially parallel over-lapping tracks or paths, and that during therolling process the pavement material becomes hardened more or less, andis rolled down into compact mass, and that as it becomes harder there isless tendency for the double roller to sink into the pavement, althoughthe stability of the machine is maintained because of its three placesof support upon the pavement. Furthermore, by reason of the great widthof the bands as compared with the width of the gap between them, thereis no tendency for the bands to form grooves or ruts in the pavement asis the case where the width of the gap between the bands is as great as,or greater than, the width of the bands. Such rollers may be used inroll ing macadam pavements, butthey would serve no useful purposewhatever in rolling down asphaltic or other plastic, hard surfacesforming pavements, because of the grooves that would result from the useof relatively narrow bands.

From actual use in rolling down street pavements, I find that anytendency for the machine to wabble or sway has been entirely eliminated,and that it is possible to roll down the street pavements withoutleaving any waves or undulations therein, on the contrary, that a smoothand even surface is obtained on crowned street pavements as well as flatones.

More or less variation of the exact details of construction is possiblewithout departing from the spirit of this invention; I desire,therefore, not to limit myself to the exact form of the constructionshown and described, but intend. in the following c aims, to point outall of the invention disclosed herein.

I claim as new, and desire to secure by Letters Patent:

1. A street paving roller, comprising in combination, a supporting framehaving a fork swiveled thereto at one end, a steering roller journaledon said forlr and a driving roller journaled on the other end ofsaidframe, said driving roller having two closely spaced tread portionsforming the major part of the tread surface of the roller, and the widthof said first mentioned roller being substantially the same as thecombined width of the two spaced tread portions of the driving rollerand the space therebetween.

2. A street paving roller, comprising in combination, a supporting framehaving a fork swiveled thereto at one end, rollers, one journaled onsaid fork and one journaled on the other end of the frame, one of saidrollers having two spaced tread portions, the total width of said treadportions and space therebetween being substantially the same as thewidth of the other roller, and the space between said tread portionsbeing less than one-half of the width of either tread portion wherebysaid tread portions form the greater part of the tread surface of saidroller.

3. A street paving roller, comprising in combination, a supporting framehaving a fork swiveled thereto at one end, a steering roller journaledin said fork, a driving drum journaled on the other end of the frame andtwo spaced tires secured on said drum, the total width of said tires andspace therebetween being substantially the same as that of the steeringroller, and the two tires comprising the major portion of the tread ofthe roller.

HARRY. 1V. LASTER,

